Polyurethane product



3,089,864 Patented May 14, 1963 4 Claims. (Cl. 260-775) This inventionrelates to a novel and useful process and product. More particularly itis concerned with a polyurethane polymer and shaped articles producedfrom it.

The commercial adaptation of the polyurethanes to the production ofshaped articles such as fibers and films has lagged due to fabricationdifficulties. The known high melting polyurethanes lack chemicalstability at temperatures required for melt processing. They also lackrequisite solubility for conventional solvent processing. Those polymerswhich have been found sufiiciently stable for melt spinning (usuallyabout 170 C.) and the like, possess melting points too low forsatisfactory fibers due to the tendency of such fibers to fuse duringironing.

It is an object of the present invention to provide a solublepolyurethane having a relatively high melting point.

Another object is to provide a polyurethane which is readily fabricatedinto a fiber or film from its solution.

It is another object to provide a polyurethane with improved hi-ghtemperature proper-ties which is prepared by a low temperaturepolymerization method.

Another object is to provide a flexible and elastic fiber and filmproduced from soluble, high melting polyurethane.

Other objects will become apparent in the course of the followingdescription and the appended claims.

In accordance with the present invention a novel and useful solublepolyurethane melting above 200 C. is produced :by reacting thebischloroformate of a beta-substituted-1,3-propanediol selected from thegroup comprising 2,2-dimethyl-l,3-propanediol and1,1-di(hydroxymethyl)cyclohexane with a carbocyclic, dip-rimary diaminecontaining no more than two discrete six-membered carbocyclic rings, theamine groups being positioned other than ortho to each other on themonocarbocyclic structure and para on each ring to the position of ringjunction on the dicarbocyclic structure, the said two discretesix-membered carbocyclic rings, when detached from each other beinglinked through a neutral bivalent group of one to four atoms in lengthand whose radical weight does not exceed 65. By a neutral bivalent groupwhose radical weight does not exceed 65 as used herein is meant astraight or branched chain structure containing in the chain, atoms suchas carbon, oxygen, sulfur and nitrogen which are non-reacting under theconditions of the polymerization. Alkylene,

represent specific examples of such groups.

The following examples are cited to illustrate the invention. They arenot intended to limit it in any manner.

which these values are determined, they provide a useful method ofevaluating the effect of process variables on a given type ofpolymerization. The values may be misleading when used to comparedifferent types of polyurethanes, but in general, those having values ofat least about 0.2 are suitable for spinning. In determining thesevalues, viscosimeter flow times are obtained at 25.0 0.1 C. for asolvent for the polyurethane and for a solution of the polyurethane inthe solvent at a concentration of 0.5 gram per 100 cubic centimeters ofsolution. The inherent viscosity value is then calculated as 2 times thenatural logarithm of the relative viscosity of the solution compared tothat of the pure solvent. Unless otherwise stated, the solvent used indetermining the inherent viscosities in the folowing examples ismeta-cresol. The melting point is taken as the lowest temperature atwhich a fresh polymer sample leaves a wet molten trail as it is strokedwith moderate pressure across a clean heated metal surface, such as abrass block. Bulk polymer is supported manually or with tweezers, andpowder or the like is manipulated with a spatula.

Example I 415 parts of phosgene are condensed in 520 parts of dioxan ina vessel equipped with a Dry Ice condenser.

A solution of 182 parts of 2,2-dimethyl propanediol in parts of water atroom temperature.

365 parts of dioxan is formed by heating the components to 50 C. Thislatter solution is gradually added with stirring to the phosgene-dioxansolution, maintaining the temperature of the combined components at 0 C.After standing for 10 hours, the excess phosgene and the hydrogenchloride formed are removed by distillation under reduced pressure(approximately 5 mm. mercury). The residue is distilled at a pressure offrom 0.5 to 1 mm. mercury. A yield, based on the diol of 2,2-dirnethylpropanediol bisehloroformate boiling at 79 C. at 0.5 mm. mercury isobtained.

. 57.2 parts of the bischloroformate of 2,2-dimethy1-1,3- propanediolprepared as described above in 750 parts of chloroform are added to arapidly stirred emulsion of 56.6 parts of 4,4-isopropylidenedianiline,58.3 parts of sodium carbonate, 1500 parts of of chloroform and 1,000After 15 minutes the emulsion is broken by addition of n-hexane. Thepolymer precipitates. It is collected by filtration and washed with anaqueous solution of 1% hydrochloric acid to render unreacted amine watersoluble. This is followed by a water wash until the collected polymer isacid free. The yield of polyurethane is quantitative, based on theamine. The polymer has an inherent viscosity of 1.21 and a polymer melttemperature of 315 C. It is soluble at room temperature in acetone,methyl ethyl ketone, methyl ethyl ketone/rnethanol (60/40), acetone/methanol (88/12), tetrahydrofuran and dimethylformamide.

Example 11 An emulsion is prepared by adding 99.1 parts of 4,4-methylene-dianiline in 880 parts of hot benzene to a rapidly stirredsolution of 106 parts of sodium carbonate, 25 parts of sodium laurylsulfate as a dispersing agent in 2,000 parts of water at roomtemperature. Thereafter 114.4 parts of the bischloroformate of2,2-dimethyl-1,3- propanediol in 440 parts of benzene is added. Theemulsion is broken with ethanol. The polymer precipitates. It iscollected and washed with ethanol to remove monomeric contaminants andthen with water. The yield is 82%. The polymer has an inherent viscosityof 2.16 and a polymer melt temperature of 305 C. It is soluble inacetone, methyl ethyl ketone, methyl ethyl ketone/methanol (60/40),acetone/methanol (88/12), tetrahydrofuran and dime-thylformamide.

Example III A solution of 28.6 parts of the bischloroformate of 2,2-dimethyl-1,3-propanediol in 300 parts of nitrobenzene is added torapidly stirred emulsion containing 25.0 parts of 4,4-oxydianiline,29.15 parts of sodium carbonate, 1,200 parts of nitrobenzene and 500parts of Water at room temperature. The emulsion is broken by distillingolf the organic solvent and the polymer is collected and Washed as inExample II. A 100% yield of the polyurethane based 011 the diamine isobtained. It is soluble in acetone, methyl ethyl ketone,tetrahydrofuran, chloroform/methanol (88/12) and dimethylformamide. Ithas a polymer melt temperature of 250 C.

Example IV A solution of 57.2 parts of the bischloroformate of 2,2-din1ethyl-1,3-propanediol in 345 parts of methylene chloride is added toa rapidly stirred emulsion containing 53.1 parts of 2,2-bi-p-toluidine,58.3 parts of sodium carbonate, 10 parts of sodium lauryl sulfate asdispersing agent, 690 parts of methylene chloride and 1000 parts ofwater at room temperature. The emulsion is broken by distilling off theorganic solvent and the polymer is collected and washed as in ExampleII. A 93% yield of polyurethane based on amine is obtained. It has apolymer melt temperature of 285 C. It is soluble in dimethylformamideand m-cresol.

Example V A solution of 28.6 parts of the bischloroformate of2,2-dimethyl-l,3-propanediol in 150 parts of nitrobenzene is added to arapidly stirred emulsion containing 23 parts of benzidine, 58.3 parts ofsodium carbonate, 5 parts of sodium lauryl sulfate as dispersing agent,300 parts of nitrobenzene and 500 parts of water. After 15 minutesn-hexane is added to break the emulsion. The polymer is isolated andwashed as in Example I. The product has a polymer melt temperature of330 C. 'It is soluble in dimethylformamide.

Example VI A solution of 28.6 parts of the bischloroformate of 2,2-dimethyl-1,3-propanediol in 300 parts of nitrobenzene is added to arapidly stirred emulsion containing 31.6 parts of 3,3-dichlorobenzidine,5 8.3 parts of sodium carbonate, 600 parts of nitrobenzene and 500 partsof water at room temperature. The emulsion is broken and the polymercollected and washed as in Example I. The polyurethane thus produced hasa polymer melt temperature of 230 C. It is soluble in dimethylformamide.

Example VI] Example VIII A solution of 57.2 parts of thebischloroformate of 2,2-

.dimethyl-l,3-propanediol in 345 parts of methylene chloride is added toa rapidly stirred mixture containing 50.3 parts of3,3'-dimethylbenzidine, 58.3 parts of sodium carbonate, parts of sodiumlauryl sulfate as dispersing agent, 690 parts of methylene chloride and1,000 parts of water at room temperature. After minutes the emulsion isbroken and the polymer collected and washed as in Example I. A yield of98% polyurethane based on amine is obtained. It has a polymer melttemperature of 4 255 C. and is soluble in hot cyclohexane,dimethylformamide and pyrrole.

Example IX A solution of 57.2 parts of the bischloroformate of 2,2-dimethyl-1,3-propanediol in 345 parts of methylene chloride is added toa rapidly stirred emulsion containing 27.0 parts of p-phenylenediamine,58.3 parts sodium carbonate, 10 parts of sodium lauryl sulfate asdispersing agent, 690 parts of methylene chloride and 1,000 parts ofwater at room temperature. After 15 minutes the emulsion is broken andthe polymer collected and washed as in Example I. A 73% yield ofpolyurethane based on amine is obtained. The polymer melt temperature is276 C., the inherent viscosity is 1.16 and the polymer is soluble indimethylformamide.

Example X A solution of 114.5 parts of the bischloroformate of 2,2-dimethyl-l,3-propanediol in 375 parts of chloroform is added to arapidly stirred emulsion containing 105.2 parts of4,4-methylenebis[cyclohexylamine] (high in trans isomers), 106 partssodium carbonate, 20 parts of sodium lauryl sulfate as dispersing agent,1,500 parts of chloroform and 2,000 parts of water in an ice cooledvessel. The solvent is boiled oil? and the polymer is isolated andwashed with hot Water. The yield is quantitative. The product has apolymer melt temperature of 225 C. It is soluble in chloroform/methanol(88/12), tetrafiuoropropanol, dimethylformamide, pyrrole and chloroform.

Example XI A solution of 57.2 parts of the bischloroformate of 2,2-dimethyl-1,3-propanediol in 690 parts of methylene chloride is added toa rapidly stirred mixture containing 14.3 parts of1,4-diaminocyclohexane, 58.3 parts of sodium carbonate, 1,380 parts ofmethylene chloride and 1,000 parts of water at room temperature. Theemulsion is broken and the polymer collected and washed as in Example I.The product is soluble in chloroform/methanol (88/12),dimethylformamide, pyrrole, acetic acid/ water (/5) andtrichloroethane/formic acid mixtures.

Example XII 57.2 parts of the bischloroformate of 2,2-dimethyl-1,3-propanediol is added over a 40 second interval to an emulsion of 219parts of benzene in 1650 parts of water containing in solution 53 partsof sodium carbonate as acid acceptor, 25 parts of sodium lauryl sulfateas dispersing agent and 35 parts of 2,4-toluenediamine at roomtemperature. After 10 minutes, the emulsion is broken by distilling offbenzene under reduced pressure. 71 parts of the polymer is collected. Itis washed with hot water and dried. It has a polymer melt temperature of210 C., an inherent viscosity of 0.93 and is soluble indimethylformamide and in a methanol/acetone solution (12/88).

Example XIII The technique of Example XII is repeated substituting 30parts of m-phenylenediamine for the 2,4-toluenediamine. A yield of 62parts of product with a polymer melt temperature of 210 C. and aninherent viscosity of 0.85 is obtained. It is soluble indimethylforrnamide and in methanol/ acetone (12/88).

Example XIV methylfo-rmamide, in a mixture of 95 par-ts acetic acid andparts water and in a mixture of 82 parts dioxan and 18 parts water.

Example XV 100 parts of phosgene are condensed in 250 parts of dioxan ina vessel equipped with a Dry Ice condenser. A solution of 72 parts of1,l-dimethanolcyclohexane in 400 parts of dioxan is slowly added to thephosgene-dioxan solution, maintaining the reactants at 0 C. Afterstanding hours, excess phosgene and hydrogen chloride formed are removedunder reduced pressure. The bischlorofo-rmate of1,l-dimethanolcyclohexane formed has a boiling point of 110 to 113 C. at5 mm. pressure.

A solution of 67.25 parts of the bischloroform tte of1,1-dimethanolcyclohexane prepared as described above in 220 parts ofbenzene is added to a stirred emulsion containing 49.55 parts of4,4-methylenedianiline, 12.5 par-ts of sod. lauryl sulfate as dispersingagent, 53 parts of sodium carbonate, 440 parts of benzene and 1,550parts of water at room temperature. The emulsion is broken and thepolymer is collected and washed as in Example II. The product has aninherent viscosity of 0.94 and a polymer melt temperature of 235 C. Itis soluble in chloroform, chloroform/methanol (88/12), methyl ethylketone, cyclohexanone, dimethylformamide and chloroform/formic acid(85/15).

Example XVI A solution of 45.6 parts of -the bischlorcfcrmate of2,2-dimethyl-1,3-propanedi0l in 175 parts of benzene is added rapidly toa stirred emulsion containing 45.2 parts of 3,3-dimethyl-4,4-diamino,diphenylmethane, 697 parts of benzene and 1200 parts of water at roomtemperature. After completion of the reaction minutes), the benzene isdistilled off. The polymer precipitates. It is collected and washed withhot Water. It has an inherent viscosity of 0.9, a polymer melttemperature of 225 C., and is soluble in dimethyltormamide.

Example XVII The polymer prepared as described in Example 11 isdissolved to produce a solution containing 18.5% solids in a methanol,acetone solvent (the proportion of methanol to acetone by Weight being12 to 88). The solution is extruded at about 52 C. under 140 pounds persquare inch pressure through a S-hole spinneret, each hole having adiameter of 0.1 mm. into a 108 C. air stream and the yarn is collectedat a wind-up speed of 46 yards per minute. The dried yarn is drawn 6times its extruded length over a 150 C. pin. It is highly crystalline,having a tenacity of 5.5 grams per denier, an elongation of 21%, aninitial modulus of 47 grams per denier, a Work recovery at 3% elongationof 89% and a tensile recovery at 5% elongation of 97%.

Example XVIII The polymer prepared as described in Example II isdissolved in dimethyl formarnide to produce a solution containingsolids. The solution is extruded through the spinneret described inExample XVII at 120 C. under 160 pounds per square inch pressure into a190 C. air stream and the yarn is collected at a Wind-up speed of 133yards per minute. It is drawn 4 /2 times its extruded length over a 170C. hot pin. It has a round cross section.

Example XIX The polymer of Example 11 is dissolved in an ethanol/methylethylketone (20/80) mixture to produce a solution containingsolids. The solution is extruded through the spinneret described inExample XXVII at 50 C. under 150 pounds per square inch pressure into a100 C. air stream and the yarn is collected at a wind-up speed of 56yards per minute. It is drawn 3 /2 times its extruded length over a 150C. hot pin. It has a peanutshaped cross section.

6 Example XX The polymer of Example I is dissolved in an ethanol/methylethylketone (20/80) mixture to produce solution containing 24%solids. The solution is extruded through the spinneret of Example XVIIas 68 C. into a C. air stream and is collected at a wind-up speed of 125yards per minute. It is drawn 3.3 times over a 90 C. hot pin, is boiledoff taut and then boiled ott relaxed. It has a tenacity of 2.1 grams perdenier, an elongation of 38% and an initial modulus of 35 grams perdenier.

Example XXI The solution of polymer prepared in Example XVII is castupon a hot plate regulated at C. Upon flashing oil of solvent, a thinflexible film form.

As previously defined the amine useful in producing the polyurethane ofthe present invention is a carbocyclic, diprimary diamine containing nomore than two discrete six-membered carbocyclic rings, the amine groupsbeing positioned other than ortho to each other on the monocarbocyclicstructure and para on each ring to the position of ring junction on thedicarbocyclic structure, the

said two discrete six-membered carbocyclic rings, when detached fromeach other, being linked through a neutral bivalent group of one to fouratoms in length and whose radical weight does not exceed 65. Such acompound is a carbocyclic, diprimary diamine of the class wherein R is amonovalent amino radical of the class of when R is an inert monovalentradical, the hexagon representing a six-membered saturated orunsaturated ring, X representing an inert bivalent radical of one tofour atoms in length and whose radical weight does not exceed 65, and Ris amino when R is an inert monova'lent radical. By the expression inertmonovalent radical is meant a radical of the class consisting ofhydrogen, halogen, cyano, methyl and methoxy. Such a radical or radicalsmay be present as a substituent or substituents on The preferred methodfor preparing the polyurethanes of the present invention, as illustratedabove is by a polymerization in an emulsion wherein water constitutesthe continuous phase while an inert water-immiscible liquid, which is asolvent for each polymeric reactant as Well as a temporary solvent forthe formed polymer, forms the dispersed phase. Benzene, nitrobenzene,methylene chloride and chloroform are typical inert, waterimmisciblesolvents satisfactory in the role of dispersed liquids. In general theWater-immiscible phase will constitute from about 40% to about 60% ofthe dispersed reaction medium. A water-soluble acid acceptor isadvantageous. Any water-soluble inorganic alkali more basic than thediamine, such as sodium hydroxide, sodium carbonate, sodium bicarbonate,borax or the like are suitable. An organic base, such as an excess ofthe diamine,

aosaaee a tertiary amine or the like may be used. While the use of adispersing agent is not essential, it is useful in attaining a highdegree of dispersion. The sodium lauryl sulfate employed in the examplesis a typical material. It is convenient in combining reactants that onebe dissolved in the organic phase of the aqueous dispersion to which isadded the second reactant dissolved in more of the same organic solvent.This technique of combining reactants may be varied by using differentsolvents for each reactant, by adding each component separately to thedispersed reaction medium or the like. Usually the diamine and thebischloroformate are added in equimolar quantities. However, a slightexcess of one or the other reactant is tolerable. The reaction usuallyprogresses well at room temperature and reaches a satisfactory degree ofpolymerization in from less than 30 minutes. At times it is advisable toslow the reaction by using lower temperatures in the neighborhood of C.The polymer may be precipitated by distilling oil? the organic phase ofthe reaction medium (preferably undcr reduced pressure), by addition ofan organic solvent in which the polymer is not soluble (such as n-hexaneor the like). The product may then be collected by filtration. It iswashed to remove unreacted monomer with hot alcohol and water or withaqueous hydrochloric acid and water.

The resulting polyurethane may be represented as composed of recurringstructural units of the general formula:

[ t t r t CO--GHzRCHgOONR-N wherein n is a large whole number, R standsfor the divalent residue and R is the residue of the diprimary diamineas previously defined (i.e., the divalent radical termed by substitutingone hydrogen of each amine group).

The solubility of the polyurethane of the present invention makes itpossible to form it into shaped articles such as fibers and films fromtheir solutions. Useful common solvents in this capacity includedimethylformamide; ketone/forrnic acid mixtures, such as acetone/formicacid, methyl ethyl ketone/formic acid; halogenated hydrocarhon/formicacid mixtures, such as chloroform/formic acid,1,2,2-trichloroethane/formic acid; ketone/ alcohol mixtures such asmethanol/acetone, ethanol/acetone. Fibers and films may be formed byconventional wet and dry spinning and casting techniques as illustratedpreviously. The solutions are also useful in the application ofcoatings, for impregnating textile materials, paper and the like.

Many modifications will be apparent to those skilled in the art from areading of the foregoing description without a departure from theinventive concept.

This application is a division of United States application Serial No.453,672, filed September 1, 1954.

8 What is claimed is: 1. A polyurethane with a polymer melt temperatureof at least about 200 C. containing recurring units of the formula:

CH2 CH2 CII Hz wherein n is a large whole number and wherein R is amember of the group consisting of and cal weight does not exceed 65 fromthe class consisting of alkylene,

2. The polyurethane of claim 1 in the form of a fiber.

3. The polyurethane of claim 1 in the form of a film.

4. A polyurethane with a polymer melt temperature of at least about 200C. containing recurring units of the formula:

wherein n is a large whole number and R is the residue of 4,4methylenedianiline.

References Cited in the file of this patent UNITED STATES PATENTS2,658,886 Swerdloff et al. Nov. 10, 1953 2,973,333 Katz Feb. 28, 1961FOREIGN PATENTS 904,471 Germany Feb. 18, 1954 OTHER REFERENCES Whitmoreet al.: J. Am. Chem. Soc., vol. 63, pages 124127 (1941).

1. A POLYURETHANE WITH A POLYMER MELT TEMPERATURE OF AT LEAST ABOUT200*C. CONTAINING RECURRING UNITS OF THE FORMULA: